Shader "Custom/HeightClip"
{
    Properties
    {
        _Color ("Color", Color) = (1,1,1,1)
        _MainTex ("Albedo (RGB)", 2D) = "white" {}
        _SubMainTex ("Sub Albedo (RGB)", 2D) = "white" {}
        _Glossiness ("Smoothness", Range(0,1)) = 0.5
        _Metallic ("Metallic", Range(0,1)) = 0.0
        _Clip("Clip", Float) = 10
    }
    SubShader
    {
        Tags { "RenderType"="Opaque" }
        LOD 200

        Cull Off

        CGPROGRAM
        // Physically based Standard lighting model, and enable shadows on all light types
        #pragma surface surf Standard fullforwardshadows vertex:vert addshadow

        // Use shader model 3.0 target, to get nicer looking lighting
        #pragma target 3.0

        sampler2D _MainTex;
        sampler2D _SubMainTex;
        float4 _SubMainTex_ST;
        half _Clip;

        struct Input
        {
            float2 uv_MainTex;
            float3 vertex;
        };

        void vert(inout appdata_full v, out Input i)
		{
			UNITY_INITIALIZE_OUTPUT(Input, i);

            i.vertex = v.vertex.xyz;
            v.vertex.y = min(i.vertex.y, _Clip);
        }

        half _Glossiness;
        half _Metallic;
        fixed4 _Color;

        // Add instancing support for this shader. You need to check 'Enable Instancing' on materials that use the shader.
        // See https://docs.unity3d.com/Manual/GPUInstancing.html for more information about instancing.
        // #pragma instancing_options assumeuniformscaling
        UNITY_INSTANCING_BUFFER_START(Props)
            // put more per-instance properties here
        UNITY_INSTANCING_BUFFER_END(Props)

        void surf (Input IN, inout SurfaceOutputStandard o)
        {
            fixed4 subColor = tex2D(_SubMainTex, IN.vertex.xz * _SubMainTex_ST.xy + _SubMainTex_ST.zw);

            // Albedo comes from a texture tinted by color
            fixed4 c = tex2D (_MainTex, IN.uv_MainTex) ;

            c = lerp(subColor, c, IN.vertex.y < _Clip);

            o.Albedo = c.rgb * _Color.rgb;
            // Metallic and smoothness come from slider variables
            o.Metallic = _Metallic;
            o.Smoothness = _Glossiness;
            o.Alpha = c.a;
        }
        ENDCG
    }
    FallBack "Diffuse"
}
